Corrugating or like treatment of sheet plastic materials



Apr. 3, 1923.

W. PATTISON 'CORRUGATING OR LIKE TREATMENT OF SHEET PLASTIC MATERIALS 3 sheeus-sheet 1 Filed May 29, 1920 Apr. 3, 1923,

W. PATTISON CORRUGATING OR LIKE TREATMENT OF SHEET PLASTIC MATERIALS Filed May 29, 1920 5 sheets-sheet 2 V Apr. 3; 1923.

W. PATTISON CORRUGATING OR LIKE TREATMENT OF SHEET PLASTIC MATERIALS- Filed May 29, 1920 5 sheets-sheet left of each stamp, and as a consequence the Patented A es, 1923.

UNITED. STATES PATENT OFFICE.

WILIIAM'PATTISON, OF WIDNES, ENGLAND.

'ooEEUGATmG 0E LIKE TREATMENT or SHEET PLASTIC MATERIALS.

Applicationifiled May 29,

To all whom it may concern: v

Be it known that I, WILLIAM PATTISON, a subject of the King of Great Britain and Ireland, and resident of Widnes, Lancaslnre. England, have invented certain new "and useful Improvements in and Relating to the Corrugating or like Treatment of Sheet Plastic Materials, of which the followlng is a specification.

This invention refers to a new or 1mproved method of and machine forcor-v rugating or similarly treating sheet plastic. materials, the chief'use of the invention being in connection with the manufacture of corrugated or shaped asbestos-cement and like sheets.

Hertofore, in making corrugated asbestoscement sheets, it has been customary to ourrugate the sheets by vertically movable stamps or formers acting downwardly upon the sheet from the centre to the edges the whole of the dead weight of the material resting .on the corrugated surface of the mould. In these circumstances the stamps in acting upon the material from the centre outwards have had to overcome the friction and weight of the material to right and sheets have frequently been spoilt by the pulling apart of the fibrous mass of which the sheet is composed.

This is especially liable to occur at the bottom of each depression, and particularly the first (central) depression where there are three conditions tending to part the sheet, viz: (1) the increased radius which that portion of the sheet which comes next the mould has to assume, (2) the pull on the sheet where the former meets it to bring it to the shape of the mould, this being the meeting point of the tension caused by reducing the overall width of the sheet, and (3) the thinning of the sheet owing to the resistance of the sheet by its own weight to the action of the formers.

The object of the present invention is to corrugate or similarly treat asbestos-cement and like sheets whilst in the plastic state so that the possibility of pulling asunder the fibrous mass, or of fracturing or thinning the sheets whilst being corrugated, shall be entirely eliminated or reduced to a minimum.

' According to the invention, each sheet to the overall width of 1920. Serial No. 385,353.

with its whole surface upon the corrugations of the mould, is normally supported clear of the corrugations and fed into position over each corrugation by its own weight, each former as it operates on the sheet to form a corrugation being relieved of the resistance of the material to the reduction of the sheet. Further, each former after moulding a part holds such part to its correct shape and is unaffected by the operations of the other formers.

In the absence of lateral tension and the possible presence of slight compression due to the manner in which the material is fed to the mould, the plastic sheets will almost be corrugated or shaped, instead "of resting of themselves (without the formers) assume approximately the positions or shapes desired and fixed for them.

The invention Will be with the aid of the accompanying drawings wherein:

Fig. 1 illustrates a longitudinal sectional elevation of a machine adapted for making corrugated asbestos-cement sheets according to the invention.

Fig. 2 illustrates a transverse sectional elevation of said machine, the section being taken on line. 22 of Fi 1.

Figs. 3 and 4 illustrate further longitudinal sectional elevations of the machine (in part) but with theoperative members in different positions.

As shown, the improvedv machine comprises a table a provided with wheels a to run on rails a Mounted on said table is a corrugated or shaped bed-plate 6, Whilst:

removably supported by said bed-plate is a sheet metal moulding-plate c. The ends b of the bed-plate are slightly raised.

Above the level of the moulding-plate and at opposite ends of the table are mounted two guide brackets 03, each guide bracket consisting of a metal plate of substantiall triangular shape, one edge of the plate being vertical and adapted to abut against the corresponding vertical edge of the adjacent guide bracket, another edge bein horizontal, whilst the third edge is incline Alongside the inclined edge are parallel flanges d forming guides. Said guide brackets are furnished with rollers e by which they are supported on the lower further described flange of girders or joists f forming the horizontal side members of the machine frame, said girders or joists being connected to each other by cross-girders or joists f and to upright members 9.

On the upper horizontal face of each guide bracket 1! are rack teeth h whilst meshing with such teeth of each guide bracket is a worm i, said worms for each pair of brackets being carried by a long shaft j common to both. \Vhilst one worm is formed with a right-hand thread the other is formed with a left hand thread the rack teeth of each bracket being formed to suit. On said shaft j on one side of the machine are two loose pulleys k and one fast pulley L provided with open and crossed belts. By means of a bevel or mitre gear and a cross shaft Z (or chain gear) the motion of one shaft is transmitted to the other shaft j on the other side of the machine. Extending across the machine are a number of heavy rollers m, the ends of which when the brackets are in the position shown in Fig. 1, extend between the fianges (l' which serve to support the rollers. The several rollers are linked together at their ends by links a. At their lower ends the bottom flanges d are bevelled off downwardly and leave a gap over which the central and lowermost roller normally lies, see Fig. 1.

Resting loosely upon the raised ends of the bed-plate I) of the table a are two light plates or boards 0, 0, which withtheir adjoining edges abutting, completely cover the top face of the former. At its outer end and near each side each board is furnished with an eye p adapted, on the outer end of the board being raised to be secured by a bolt or pin 9 to an eye 1' on the outer end of the adjacent bracket. With each board thus secured to a bracket it is held in an inclined position both boards inclining downwards towards the centre of the table.

On each guide bracket is journaled a short shaft 8 carrying at one part a drum t and at another part a spur wheel t. Connected to said drum is one end of a wire cable 25 whilst the other end of said cable, after passing-over a guide wheel F, is connected to the endmost roller m. The spur wheel 75 gears with rack teeth u on the underside of the girder or joist f. lVith the guide brackets in the position shown in Fig. 1, the wire cable holds the rollers in the raised position.

In proceeding to use the improved machine for fluting or corrugating a sheet of asbestos-cement, the latter (which will usually be equal in length to and slightly wider than the former plate 0) is placed on the boards 0, 0, these latter then being detached from the brackets and lying fiat on thetable as shown by dotted lines in Fig. 1. The boards are then raised at their outer ends and bolted to the brackets, thereby folding the sheet of asbestos-cement to a V-shape or holding those parts of the sheet to right and left of its centre inclined. The open belt is then moved on to the-fast pulley 7: whereupon the shaft j and worms '5 are rotated and the pairs of guide brackets 11, d on the two sides of the machine slowly separate from each other.

As the guide brackets d move away from each other the lowermost roller m is lowered on to the sheet of asbestos-cement, which being in a plastic condition is caused by the weight and shape of the roller to conform to the shape of the central corrugation of the former-plate 0, the other parts of the sheet readily responding to the pull of the roller, owing to their being free and owing also to their being fed by gravity down the boards 0, 0: As the guide brackets d further '85 separate the other rollers m are lowered on to the sheet one by one from each guide bracket, each roller shaping a portion of the sheet before the next roller of the same guide bracket touches the material. In Fig. 3,-the first three rollers are shown lowered on to the plastic sheet and in Fig. 4 nine rollers are shown lowered.

In this way the'whole width of the sheet is corrugated, the rollers next the endmost rollers being lowered on to the sheet, on the guide brackets being separated the furthest distance apart and only one or two rollers remaining in each guide, see Fig. 4.

With the plastic sheet fully corrugated the open belt is moved on to one of the loose pulleys I: and the crossed belt moved on to ion the fast pulley is thereby reversing the direction of movement of the brackets d, which through the medium of the Wheels t, racks u, drums t, and cables 25 cause the rollers m to be drawn up into the guides, until they again occupy the positions shown in Fig. 1.

The boards 0, 0, may be detached from the brackets 03 prior to or after moving the brackets back to the original position.

The table a and with it the mouldingof their traverse may be done by hand or it may be done automatically by one of the brackets operating to release a catch which holds the. operative belt on the fast pulley against the pull of a spring or weight. In

place of only three pulleys there may be our, i. e., two fast and two loose.

Whilst chiefly for use in corrugating asbestos-cement sheets, the invention may be adapted for corrugating other plastic materials in sheet form. Further, it may be used for corrugating sheets requiring only to be corrugated at intervals in its width.

By the substitution in place of the rollers m of unit former members of other shapes (say square, triangular or other suitable sections of bars) and by the substitution of a former-plate on the table a of corresponding pattern, other than curved corrugations may be formed in the plastic material.v In this connection, eaves, gutters, channels, copings, sections, angles and the like may be made in the improved machine. J

IVhat I claim is 1. In the method of corrugating or shaping asbestos-cement and like sheet plastic' materials progressively from a point central to the width of the sheet towards each side edge by upper and lower formers, supporting the sheet clearof the lower former and upon inclined travelling supports, whereby the upper formers as they act on the material are relieved of the dead weight resistance and a considerable part of the friction of the uncorrugated parts of the sheet substantially as herein set forth.

2. In a method of corrugating or shaping asbestos-cement and like sheet plastic materials progressively from a point central to the width of the sheet towards each side edge by upper and lower formers, holding the sheet so as to allow it to feed itself by gravity on to the lower former, substantially as herein set forth.

3. In a machine for corrugating or shaping asbestos-cement or like sheet plastic materials, pairs of travelling guide brackets on each side of the machine, each bracket of each pair having inclined guides for the reception of. the ends of a series of cylindrical bars or like unit formers and each bracket carrying means whereby in conjunction with the fixed frame of the machine as the brackets separate the said rollers are progressively lowered on to a relatively stationary former or moulding-plate, and whereby as the brack-.

ets approach each other, the said rollers are raised, and held clear of the lower former, substantially as herein set forth.

4. In a machine for corrugating or shaping asbestoscement or like sheet plastic materials, a series of cylindrical bars or like unit formers mounted on guide brackets each of which comprises a plate of approximately triangular outline and said plate having rack teeth on its top horizontal edge and flanges near its inclined edge, rollers for supporting the bracket from a girder or like support, and a drum, cable, guide roller and toothed wheel for operating the upper unit formers to raise or lower the same, substantially as herein set forth.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

WILLIAM PATTISON.

Witnesses:

-HY. J UNCA,

W. HARRIS TETTLE. 

